Abstract: A system may include a reactor vessel comprising an outer wall, a heat source thermally coupled to the reactor vessel, at least one reactor inlet in the outer wall, and at least one reactor outlet. The reactor vessel may be configured to house a porous preform in a radially central core region. The at least one reactor inlet may be configured to introduce a precursor gas to the reactor vessel to produce swirling flow of the precursor gas around the radially central core region of the reactor vessel. The at least one reactor outlet may be configured to remove exhaust gas from the reactor vessel and assist in maintaining a dynamic pressure of the reactor vessel greater than a pressure in the porous preform.

Abstract: A method of forming a moisture-tolerant coating on a silicon carbide fiber includes exposing a silicon carbide fiber to a gaseous N precursor comprising nitrogen at an elevated temperature, thereby introducing nitrogen into a surface region of the silicon carbide fiber, and exposing the silicon carbide fiber to a gaseous B precursor comprising boron at an elevated temperature, thereby introducing boron into the surface region of the silicon carbide fiber. Silicon-doped boron nitride is formed at the surface region of the silicon carbide fiber without exposing the silicon carbide fiber to a gaseous Si precursor comprising Si. Thus, a moisture-tolerant coating comprising the silicon-doped boron nitride is grown in-situ on the silicon carbide fiber.

Abstract: A ceramic matrix composite component for use in a gas turbine engine and method for making the same are described herein. The component includes a body and an outer region. The body includes a silicon containing ceramic composite. The outer region is on an outer surface of the body.

Abstract: A system may include a reactor vessel comprising an outer wall, a heat source thermally coupled to the reactor vessel, at least one reactor inlet in the outer wall, and at least one reactor outlet. The reactor vessel may be configured to house a porous preform in a radially central core region. The at least one reactor inlet may be configured to introduce a precursor gas to the reactor vessel to produce swirling flow of the precursor gas around the radially central core region of the reactor vessel. The at least one reactor outlet may be configured to remove exhaust gas from the reactor vessel and assist in maintaining a dynamic pressure of the reactor vessel greater than a pressure in the porous preform.

Abstract: A method of forming a moisture-tolerant coating on a silicon carbide fiber includes exposing a silicon carbide fiber to a gaseous N precursor comprising nitrogen at an elevated temperature, thereby introducing nitrogen into a surface region of the silicon carbide fiber, and exposing the silicon carbide fiber to a gaseous B precursor comprising boron at an elevated temperature, thereby introducing boron into the surface region of the silicon carbide fiber. Silicon-doped boron nitride is formed at the surface region of the silicon carbide fiber without exposing the silicon carbide fiber to a gaseous Si precursor comprising Si. Thus, a moisture-tolerant coating comprising the silicon-doped boron nitride is grown in-situ on the silicon carbide fiber.

Abstract: A ceramic matrix composite component for use in a gas turbine engine and method for making the same are described herein. The component includes a body and an outer region. The body includes a silicon containing ceramic composite. The outer region is on an outer surface of the body.

Abstract: A ceramic matrix composite component for use in a gas turbine engine and method for making the same are described herein. The component comprising a body and an outer region. The body having a silicon containing ceramic composite. The outer region on an outer surface of the body.

Abstract: Extremely hard, fine grained tungsten/carbon alloys are described which are produced by thermochemical deposition. The alloys consist primarily of a mixture of a substantially pure tungsten phase and at least one carbide phase wherein the carbide phase consists of W.sub.2 C or W.sub.3 C or a mixture of W.sub.2 C and W.sub.3 C. The disclosed tungsten/carbon alloys are free of columnar grains and consist essentially of extremely fine, equiaxial crystals. Also disclosed is a method of producing the disclosed material.

Abstract: A method for producing the disclosed material comprises introducing into a chemical vapor deposition (CVD) reactor a mixture of process gases comprised essentially of (1) tungsten hexafluoride, (2) a volatile oxygen- and hydrogen-containing organic compound, and (3) hydrogen; controlling the ratio of the tungsten hexafluoride to the oxygen- and hydrogen-containing organic compound within the CVD reactor so that the W/C atomic ratio is within the range of about 0.5 to about 15; controlling the reaction temperature so it is within the range of above about 300.degree. to less than about 650.degree. C.; controlling the total pressure within the range of about 1 Torr. to about 1,000 Torr.; and controlling the ratio of H.sub.2 to WF.sub.6 within the range of about 4 to about 20; to produce W and W.sub.2 C, W and W.sub.3 C, or W and W.sub.2 C and W.sub.3 C.